Ya I agree with it. But I dont feel that it is effective enough. Not to mention Google might be having about millions or billions of Adwords advertisers across the world.
And i this case after you scrutinize and restrict the low paid ads from displaying on your site, then there isant any assurity that google wont display low paying ads from other advertisers from their database of millions of advertisers again on your site.
May be this can work if you repeatedly scrutinize your ads every 15 days or month.